If you were talking anywhere besides NYC, I'd say "No problem." American hotel rooms can almost always sleep four people comfortably if there are two doubles. (When I say "comfortable" I mean it in the four-college-students-roadtripping sense.)

NYC is a bit of a different beast. If there really are two doubles in the room, I still think you should be OK. We've put four guys in an NYC room when we *thought* there were going to be two doubles, and we ended up with two twins and two guys sleeping on the floor. (Sounds like the same gig as you - we were on a college roadie, hitting baseball stadiums as we went, staying in cheap hotels along the way. At that time, Manhattan rates weren't quite as absurd, so staying in Jersey or Queens wasn't necessary.)

So, check out the total area of the room (it'll be listed in square feet - divide by 10.75 or so to get sq.meters) - and double-check bed types.